[Jake2]

One other change has made a surprising further uplift: a set of new Black Ravioli Big Pad Plus footers under my Signature Rendu SE streamer, replacing standard Big Pads. It's hard to credit just how good these footers are until you hear the increased tightness in the bass and the cleaner peaks. Mine are an evaluation set, they have not yet been released and there is no final pricing as yet. I shall be acquiring a second set for the DAC when I am able.

Thanks to @Mr Brett kindly loaning me his Black Ravioli Big Pads today to try I can vouch for these BR pads generally if not the new Plus version. Remarkable for difference they make - hard to describe, but they bring a lovely finesse and delicacy to transient edges and note decay that I won’t want to give up. Within half an hour of listening I was online requesting a shipping quote.

 

[MartinWT]

Ah, that was nice of Brett but then he is proper a gentleman.

Most of my system uses Big Pads but both the Rendu and DDC/DAC/clock are on Big Pad Plus and they are truly remarkable.

I'll be getting my Sig Rendu SE upgraded to Deluxe version later this week. I can't wait to hear the difference.

 

[TheRealDz]

I have a question; is a clock signal to both a DDC and to a DAC redundant?

First of all, I want to reiterate that I am a believer in outboard clocks; my Aune makes a huge difference in the soundstage of my system, as does even the generic clock that I recently purchased. But I am trying to determine whether two clock connections are better than one.

I recently purchased a Singxer SDA-6 Pro 2 DAC. It is quite an excellent DAC for the price. As far as I can tell, it is also the lowest price DAC with a clock input.

The clock input is active on the USB, Coax, and AES inputs, but it is unclear whether it is active for the I2S input. I asked Singxer, and they didn't really answer my question other than to say that a clock signal to a DAC is not necessary if a DDC is connected, since the I2S connection carries the clock signal from the DDC.

So is there a benefit to running my clock to the DDC and the DAC? I know that folks report great results running clocks into both their DDC and to DACs such as Gustard's A26/R26. I don't know whether their clock inputs have different internal configurations than my SDA-6 does.

So with all the positive feedback of A26/R26 owners, what could Gustard be doing? How does Gustard account for the clock signal contained in the I2S connection vs the DAC's clock input?

I appreciate your thoughts on this!

 

[Jake2]

I have a question; is a clock signal to both a DDC and to a DAC redundant? First of all, I want to reiterate that I am a believer in outboard clocks; my Aune makes a huge difference in the soundstage of my system, as does even the generic clock that I recently purchased. But I am trying to determine whether two clock connections are better than one.

I recently purchased a Singxer SDA-6 Pro 2 DAC. It is quite an excellent DAC for the price. As far as I can tell, it is also the lowest price DAC with a clock input.

The clock input is active on the USB, Coax, and AES inputs, but it is unclear whether it is active for the I2S input. I asked Singxer, and they didn't really answer my question other than to say that a clock signal to a DAC is not necessary if a DDC is connected, since the I2S connection carries the clock signal from the DDC.

So is there a benefit to running my clock to the DDC and the DAC? I know that folks report great results running clocks into both their DDC and to DACs such as Gustard's A26/R26. I don't know whether their clock inputs have different internal configurations than my SDA-6 does.

So with all the positive feedback of A26/R26 owners, what could Gustard be doing? How does Gustard account for the clock signal contained in the I2S connection vs the DAC's clock input?

I appreciate your thoughts on this!

There's not necessarily a black and white answer to this question - or if there is I don’t know it - you’ll likely need to seek clarification from Singxer or see if you can google the answer.

By way of illustration when we sought clarification from Gustard as to when the R26 refers an external clock the answer was:
- all inputs, both synchronous (i2S and s/pdif etc) and asynchronous (USB etc) when oversampling is ON (I.e
PCM NOS/DSD Direct OFF) get the benefit of a connected external clock
- when oversampling is OFF (I.e. PCM NOS/DSD Direct ON) then only asynchronous inputs like USB and Ethernet benefit from the external clock. This would fit with conventional wisdom that the clock signal contained in the I2S feed is used by most DACs rather than their internal (or externally connected) clock. The exception is DACs that always reclock all inputs, Audio-Gd is an example I believe.

In practice I still observed an audible, if more subtle, benefit in the second case with I2S & NOS ON - my best guess is that although the master clock signal in the i2S signal is (per Gustard) being used untouched the PLL in the R26 is likely referring the external clock signal so is operating with greater precision.

As to what happens with Singxer DACs I can only speculate. Send them a message is my suggestion, hopefully there’s less of a language barrier than with Gustard. Good luck.

I should add, in my experience there is a benefit with the R26 to externally clocking both the DDC and the DAC when using I2S. YMMV of course.

 

[sajunky]

The exception is DACs that always reclock all inputs, Audio-Gd is an example I believe.

Audio GD do not reclock asynchronous input, in this case there is only USB. I think you have mistaken Audio GD with Denafrips that reclocks all inputs. It is stated on the website, maybe not clear in English. In esence it says that oscilators from the Amanero module are removed, using internal clock feeding Amanero back (through the galvanic isolator) and the same clock feeds FPGA. In such design there is no added jitter on the USB connection as long it is asynchronous. It applies both to DDC, R-8/R-7 and HE7 DACs since 2021, no exception.

Such solution has its downside. While a top sound quality is achieved when everything goes right, sound can be degraded to the level of ~20 years ago when USB had poor reputation. In the case of any disruption of USB protocol resulting that host decide to downgrade connection to some older compatibility mode, it not good. Therefore care should be taken when using USB 'reclockers' or external cards with poor drivers. Recently there was a case where JCAT USB card with unstable external power connection started producing poor sound, it required reboot. In the same situation Denafrips will reduce jitter to the comfortable level, user may not notice.

Gustard has its own peculiarities which indicate rather poor integration of open source components without modifications than a thorough engineering. And communication returns different versions, depends what answer user expects to see. We can't depend on what they say, trust your ears

A word on external clocks. With the proper engineering external clock makes no difference to the chosen internal clock synchronisation method. It is just a matter of switching a source from the internal fixed frequency oscilator to the external 10MHz source which must go though a synthesizer. The exception is I2S where it is asumed that I2S clock source is a good quality. There is a decision to take at the designer desk it is not clear what is better. It needs to be verified in practice.

 

[MartinWT]

Just to add to the above, I feed a clock to my U18 DDC and that passes through the clock via I2S to my X26 Pro DAC, so they both benefit.

 

[Jake2]

Audio GD do not reclock asynchronous input, in this case there is only USB. I think you have mistaken Audio GD with Denafrips that reclocks all inputs. It is stated on the website, maybe not clear in English. In esence it says that oscilators from the Amanero module are removed, using internal clock feeding Amanero back (through the galvanic isolator) and the same clock feeds FPGA. In such design there is no added jitter on the USB connection as long it is asynchronous. It applies both to DDC, R-8/R-7 and HE7 DACs since 2021, no exception.

Such solution has its downside. While a top sound quality is achieved when everything goes right, sound can be degraded to the level of ~20 years ago when USB had poor reputation. In the case of any disruption of USB protocol resulting that host decide to downgrade connection to some older compatibility mode, it not good. Therefore care should be taken when using USB 'reclockers' or external cards with poor drivers. Recently there was a case where JCAT USB card with unstable external power connection started producing poor sound, it required reboot. In the same situation Denafrips will reduce jitter to the comfortable level, user may not notice.

Gustard has its own peculiarities which indicate rather poor integration of open source components without modifications than a thorough engineering. And communication returns different versions, depends what answer user expects to see. We can't depend on what they say, trust your ears

A word on external clocks. With the proper engineering external clock makes no difference to the chosen internal clock synchronisation method. It is just a matter of switching a source from the internal fixed frequency oscilator to the external 10MHz source which must go though a synthesizer. The exception is I2S where it is asumed that I2S clock source is a good quality. There is a decision to take at the designer desk it is not clear what is better. It needs to be verified in practice.

Cheers, my bad re AudioGd reckclocking, will add a correction.

 

[OCC7N]

I recently purchased a Singxer SDA-6 Pro 2 DAC. It is quite an excellent DAC for the price. As far as I can tell, it is also the lowest price DAC with a clock input.

https://ifi-audio.com/products/neo-idsd-2/
Best part is power supply can be changed as it is DC.
----
In entry level(price) always go for something with DC. Rule nr1. Unless it has a special/good power implementation. It is a freedom to elevate the performance/level higher than stock.